The invention relates to a displacement device.
From DE 41 20 617 C2 a displacement device is known which has a load torque lock with which torque on the drive side is transferred in both directions to an output element while torque on the output side is blocked in both directions by the load torque lock and the force is introduced into a displacement housing and is consequently not transferred to the drive element.
Between the drive element and the load torque lock the torque on the drive side is transferred by means of elements which engage in each other with keyed engagement. Since the position of the locking elements of the load torque lock changes through tolerances and wear as a result of high flat surface pressures, in order to reach the required functional reliability of the known displacement device it is necessary to incorporate a large play so that during functioning a torsion angle play is present between the interengaging elements without which a stepped transfer or change of direction of the torques on the drive side is not possible. A minimum torsion angle play must also therefore be present between the interengaging elements of the drive element and the load torque lock in order to guard against wear and enable a certain elastic deformation.
Opposite this however too much torsion angle play, particularly in the case of a stepped transfer of the torque on the drive side, has a noticeable detrimental effect since the torsion angle play causes a correspondingly large idling path or idling stroke of the drive element. Furthermore too much torsion angle play can lead, when reversing the movement, to a detrimental reversal play and to inaccurate handling.
The known displacement device has a relatively large reversal play in the brake unit conditioned by the tolerances of the structural parts. In order to restrict this, manufacture must be carried out precisely within a narrow tolerance band. The assembly of the individual component parts which are provided with small tolerances is therefore expensive since the component parts which are to be connected together have to be positioned very precisely relative to each other.